Movable bolster for metal working press



Oct. 3, 1961 E. K. JOHANSEN ETAL 3,002,479

MOVABLE BOLSTER FOR METAL WORKING PRESS Filed June 10, 1957 '7 Sheets-Sheet 1 INVENTORS:

EINAR K. JOHANSEN GORDON M. SOMMER 7 Oct. 3, 1961 E. K. JOHANSEN ETAL 3,002,479

MOVABLE BOLSTER FOR METAL WORKING PRESS Filed June 10, 1957 7 Sheets-Sheet. 2

FIG 6 FIG. 5

INVENTORS: EINAR K. JOHANSEN GORDON M. SOMMER ATT YS Oct. 3, 1961 K. JOHANSEN ETAL 3,00

MOVABLE BOLSTER FOR METAL WORKING PRESS Filed June 10,1957 7 SheetsSheet 3 IN VEN TORS I EINAR K. JOHANSEN GORDON M. SOMMER Oct. 3, 1961 Filed June 10, 1957 E. K. JOHANSEN ETAL MOVABLE BOLSTER FOR METAL WORKING PRESS 7 Sheets-Sheet 4 INVENTORS: EINAR K. JOHANSEN GORDON M. SOMMER Oct. 3, 1961 E. K. JOHANSEN ETAL 3,002,479

MOVABLE BOLSTER FOR METAL WORKING PRESS Filed June 10, 1957 7 Sheets-Sheet 5 FIG. l2

mm iiWi FIG. I4

INVENTORS I EINAR K. JOHANSEN GORDON M. SOMMER Oct. 3, 1961 E. K. JOHANSEN El AL MOVABLE BOLSTER FOR METAL WORKING PRESS Filed June 10, 1957 7 Sheets-Sheet 6 FIG. I?

I INVENTORS: EINAR K. JOHANSEN GORDON M. SOMMER W ,LMJJ

ATT 'YS Oct. 3, 1961 E. K. JOHANSEN ETAL 3,002,479

MOVABLE BOLSTER FOR METAL WORKING PRESS Filed June 10, 1957 7 SheetsSheet 7 FIG. I8

k \S I A X muii" i I i -20 j |s l I a m I8 I l & 2| L I l9 wi L i 22 K 22 25 I I L 1 1 k \W -a*""m\ INVENTORS EINAR K. JOHANSEN and GORDON MVSOMMER by *Kwi 3,002,479 .1 MOVABLE BOLSTER NHETAL WORKING This invention relates in general to an improved metal working press, and more particularly to a metal working press constructed to materially reduce die changing time and thereby increase the production of an individual press.

Die changeover in an individual press is normally timeconsuming during which time it is necessary to shut down operation of the press. Such shut downs obviously reduce the productive output of the press within any given period of time, and therefore are objectionable and undesirable. While this problem may not be important to the manufacturer that continues to run the same job on an individual press for days, weeks, months or the like, it is paramount importance to the manufacturer who has many required die changes due to limited production of any given part. A specific example of this is in commercial job shops where die changing time can mean the difference between profit and loss on' a job. Further, where die changing requires shut down of a press for a considerable time, manufacturers have run' excess quantities of parts only to find themselves strapped with the necessity of allocating storage space and pay intime and money for the handling and maintenance. of a large inventory.

Accordingly, it is an object of this invention to provide an improved metal working press which obviates the above set forth difficulties ,by materially reducing die-changing time and thereby reducing shut-down time of the press and consequently increase individual press production.

Another object of this invention resides in the provision of a metalworking press having a movable bolster,

wherein operation of the press may be continued with one bolster and set of dies in the press while another set of dies may be mounted on a similar bolster outside of the press.

Still another object of this invention is in the provision of a metal working press having movable bolsters wherein die changing may be accomplished easily and quickly in a minimum amount of time thereby eliminating the need for large parts inventory since it is more economical to run limited quantities of a part several times than it is to allocate storage space and pay in time and money for the handling and maintenance of a large inventory.

A further object of this invention is to provide a metal working press having movable bolsters wherein die changing time may be held to a minimum even on those jobs where time can mean the difference between profit and loss. A still further object of this invention is inv the provision of a metal working press having a movable bolster wherein a diiferent die may be set up on a bolster outside of the press while the press is still running and using a previous die thereby substantially reducing press-down time which may be measured in minutes now instead of hours, and wherein a nearly continuous production run may be accomplished for many short run parts.

Other objects, features and advantages of the invention will be apparent from the following detailed disclosure taken in conjunction with the accompanying sheets of drawings, wherein like reference numerals refer to like parts, in which:

FIG. 1 is a perspective view of a metal working press embodying the present invention;

. FIG. 2 is a top plan view .ofa metal working press,

ted StatcshPflt O taken substantially along line 22 of FIG. 3, with some parts in section and other parts in dotted lines to illustrate positioning of underlying parts;

FIG. 3 is a longitudinal sectional view of the press taken substantially along line 3-3 of FIG. 2 and show,- ing the bolsters arranged in clamped position for operating the press;

FIG. 4 is a top view of the anti-deflection coupling utilized between the connected movable bolsters in accordance with the invention;

FIG. 5 is a vertical sectional and elevational view of the press according to the invention, taken substantially along line 5-5 of FIG. 2;

FIG. 6 is an enlarged detail sectional view taken from the circled section 6 of FIG. 5; v

H6. 7 is a view similar to PEG. 3 but showing the parts in a difierent position, wherein the bolster in FIG. 7- is unclamped from the press bed and arranged to be moved;

FIG. 8 is a sectional view, taken substantially along line 8-8 of FIG. 7;

FIG. 9 is a detailed enlarged sectional view taken from the circled section 9 of FIG. 8;

FIG. 10 is a longitudinal elevational view similar to FIG. 3, but showing the bolsters at the opposite end of the tracks and in unclamped position;

FIG. 11 is a view similar to FIG. 10 but showing the bolsters in clamped position;

FIG. 12 is a vertical sectional view taken through the press of FIG. 1 and illustrating the die as related to the other parts of the press; j

FIG. 13 is a top plan view of one of the movable bolsters;

FIG. 14 is an enlarged fragmentary sectional view, taken substantially along line l4-l4 of FIG. 13;

FIG. 15 is a perspective view of a modification of the invention;

FIG. 16 is an end elevational view, partly in section, similar to the view of FIG. 5, but taken through the modified arrangement of FIG. 15;

FIG. 17 is a fragmentary side elevation view of one end of a movable bolster taken along line l7--l7 of FIG. 16; and

FIG. 18 is an enlarged vertical sectional view taken through the die cushion.

An example of the preferred embodiment of this invention as illustrated in FIGS. 1 to 14, inclusive, deals with a press construction having a pair of moving bolsters connected together, wherein one of the bolsters will normally be in use supporting a die within the press, while the other bolster will be positioned outside of the press where the mounting of another die on this latter bolster may be accomplished while the press is in operation. The usual die or die set will include a punch or lower die mounted on the lower die shoe which is secured to the top of the bolster, a draw ring operable by the die cushion in the press and an upper die secured to the face of the slide. If a draw ring is not needed, operation of the die cushion may be dispensed with. Thus, it can be appreciated that the lower die and die shoe are secured to the bolster when it is outside of the press and that the upper die will be properly positioned on top of the lower die so that the entire die or die set may be moved together into the press, at which time the upper die may be secured to the face of the slide. Further, the bolster will then be secured to the bed of the press to assure stability during operation. Final adjustment of the bolster will be made before it is clamped or secured tightly to the press bed, and the usual slide adjustments may also be made before the press is put into operation.

A modification of the preferred embodiment consists essentially of substituting a single bolster for the double bolster arrangement, wherein ,die setting on a single 3 bolster may be accomplished in a centralized area of the plant rather than right at the press.

Referring now particularly to the drawings and to the embodiment illustrated in FIGS. 1 to 14, the press, generally designated by thenumeral 10, includes generally a' press bed 11, a crown 12 spaced thereabove, and four uprights 13 supporting the crown 12 above the bed 11. A slide 14 is vertically driven between the uprights, and a double moving bolster assembly 15 is movable from right to left and left to right over the bed 11 and between the uprights 13. The moving bolster assembly 15 as illustrated herein is movable through the opposite sides 'of the press, although it will be understood that it may also be movable through the front and the back of the press. Further, although the present invention is illustrated in association with a top drive press, it will be understood that it may also be used with a bottom drive press.

Mounted in the press bed 11 are a pair of die cushions 16 in side-by-side relationship for operating a draw ring of a die set. While two die cushions are shown with the present press construction, it will be appreciated that one may be utilized or that more than two may be utilized in some instances. A single control panel 17 on one of the uprights 13 as seen in FIG. 1, through electrical and hydraulic circuits, controls the entire operation of the press and movable bolster arrangement for die changing and the like, although the circuits do not form a part of the invention. With such a single control panel, push-button die setting is accomplished to make the die changing easy and quick.

Each die cushion as seen in FIG. 3 includes a pneumatic cylinder 18 mounted on a cross member 19 of the bed and movably supporting a pressure pad 20 which is driven up and down to control operation of the draw ring. A plurality of rods 21 are secured to the pressure pad '20 and extend through the cross member 19. At the lower end of these rods, adjustable stop nuts 22 are carried to bear against the underside of the cross member 19 when the pressure pad is in its upper position and thereby prevent the pressure pad 20 from hitting or striking the bolster and disturbing same during the metal forming operation. Since it is sometimes diflicult to lower the pressure pad 20 when no force is exerted against the draw ring, and it is necessary to retract the pressure pad when making a die change for moving the double bolster assembly 15, an auxiliary pull down cylinder 23, mounted on a cross member 24 parallel spaced below .the cross member 19, and having its piston connected to the pressure pad 20 by means of the rod 25, which extends upwardly through the cylinder, may be actuated to retract the pressure pad. Normally, the piston of the cylinder 23 will move up and down with the pressure pad 20 so it is only necessary to have the cylinder 23 as a single acting cylinder for movement of the pressure pad in one direction.

Referring now to FIG. 12, an example of the type of die that may be employed in the present invention is illustrated wherein the die, generally designated by the numeral 26 includes a lower die shoe 27 secured to the top of the bolster, a punch or lower die 28 mounted on the die shoe 27, an upper die 29 secured to the face of the slide 14, and a draw ring 30 resting on the lower die shoe 27 and arranged in association with the lower die .28. The upper die 29 is clamped to the slide14 by hydraulically operated die clamps 31, FIGS. 1 and 12,

which may be remotely operated from the control panel 17. Although the detailed structures of the die clamps do not form a part of the invention, they include generally a hydraulic cylinder 32 operating through linkages to control a clamping bolt or locking arm 33 which engages an outwardly extending flange of the upper die 29. .Essentially, a flange on the slide is connected to a flange on the die. These die clamps may be operated very quickport bars 44 of each bolster.

1y to disengage or engage a die to the slide thereby facilitating a quick changing operation.

The double bolster assembly 15 includes bolsters 34 and 35 arranged in end-to-end relationship and pivotally connected together by one or more anti-deflection couplings 36, FIGS; 3 and 4. Each coupling includes a plate 37 bolted to one of the bolsters and pivotally connected to the other bolster by means or a horizontally extending pin 38. The normal reaction of the bolster in the bed to the pressure of the slide during operation of the press which causes the bolster in the press to bow or bend in the middle is completely absorbed by one or more of these anti-deflection couplings thereby preventing deflection of the bolster being set up outside of the press. Accordingly, the adjacent connected ends of the bolsters are pivotal relative to each other on a horizontal ms.

For the purposes of mounting the lower die shoe 27 and the lower die 28 to the top of the bolster, each bolster is provided on its top with a plurality of transversely extending parallel spaced T-slots 39 which are adapted to receive T-bolts for securing. the lower die shoe in any desired location on the bolster in the usual manner as seen in FIGS. 13 and 14. While two sets of T-slots are dis closed on the bolster in FIG. 13, it will be appreciated that only one set may be used, but that with two sets, two different dies may be mounted on the bolster at one time.

The top of the bolster is also provided with a plurality of vertically arranged holes or apertures 40 for slidably receiving pressure pins 41. These pressure pins are freely removable so that they may be set into any pattern desirable or necessary in order to operate the draw ring. In the present arrangement, the pressure pins are arranged as seen in FIG. 13 in a substantially square pattern. The lower ends of the pressure pins rest on a pressure pin carrier or pressure pin support plate 42, FIG. 12, which in turn is normally suspended in the bolster by inwardly extending ledges 43 formed on lower longitudinal sup- Holes are also provided in the lower die shoe 27 which may be aligned with the holes in the bolster so that the pressure pins 41 may extend upwardly therethrough and engage at their upper ends the underside of the draw ring 30, as seen in FIG. 12. Thus, each bolster is constructed in such a manner as to have pressure pin carriers for supporting pressure pins in any desirable fashion for operating a draw ring. Rotatably mounted at the undercarriage and outer ends of the bolsters 34 and 35 are a pair of transversely spaced flanged wheels 45 which rollably support the bolsters along sets of tracks or rails 46 and 47, FIGS. 2, 3 and 4, one set extending from each side of the press. The tracks 46 are mounted .on one side of the press while the tracks 47 are mounted on the other side, and each set of tracks extend inwardly slightly into the press between the uprights. These tracks are aligned and guide the bolsters along a predetermined rectilinear path relative to the press and its components. Additionally supporting the bolsters for movement when they are within the confines of the press are four wheels or rollers 48 each rotatably carried by a vertically movable cylinder 49 of a hydraulic cylinder 50. The piston 51 of each of the cylinders 50 is rigidly secured to a brace 52 of the bed and therefore anchored to the bed. As seen in FIG. 2, these cylinders are'arranged so that their wheels are in pairs and engage the undersides of the opposed support bars 44 of the bolsters 34 and 35. The hydraulic cylinders 50 may be single or double-acting as either will serve the purpose desired and it will be understood that the bolsters 34 and 35 may be raised or lowered by simultaneous operation of all of these cylinders.

At the inner ends of the tracks 46 and 47, wheel recesses 53 and 54, respectively, serve to respectively receive the wheels 45-0f the bolsters 34 and 35 to allow lowering of the bolsters so that the opposed support bars '44 intimately engage the top surface of the bed when the justed prior to moving of the bolster within the the bolster is then moved thereagainst.

jj arrangement.

cylinders 50 are operated to lower the support wheels 48.

V This effects a firm foundation for the bolster being used within the press during operation of the press. The wheels 48 in FIG. 3 are shown in their down position with the bolster 35 within the press being in intimate engagement with the top of the press bed 11 and also the wheels 45 being received in the recesses 54, while FIG. 7 shows the wheels 43 in the up position and the wheels 45 of the bolster 35 being out of the wells or recesses at the inner ends of the tracks 47.

Inasmuch as it would be undesirable for the bolster outside of the press, such as a bolster 34 in FIG. 3, to be in a tipped condition since the inner end connected'to the anti-deflection coupling 36 would be down when the bolster 35 is in engagement with the bed 11, movable track sections 55 in the tracks 46, and movable track "sections 56 in the tracks 47 are provided, each of which is mounted on a cylinder 57 of a fluid or hydraulic cylinder 58 Each cylinder 57 is associated with a piston 59 mounted rigidly on a brace 60 below the levels of the tracks. Accordingly, the hydraulic cylinders 58 may be operated to raise or lower the track sections 55 and 56 which when in the lowered position define recesses or wheel wells for receiving the wheels 45 of the bolsters 34 and 35 thereby lowering the outer ends of the bolsters to provide a bolster with a level upper surface and thereby facilitate mounting of a die thereon. It may there- 'fore be appreciated that all of the hydraulic cylinders 58 'and the hydraulic cylinders 50 may be single or doubleacting and will be operated at substantially the same time "in order to raise or lower the bolsters in accordance with "the operation desired. a .Since the lower die and lower die shoe will be rigidly secured to the bolster outside of the press according to a -preset pattern arrangement, it is necessary to accurately position the bolster within the press so that the upper die may be easily secured to the slide and coact properly with the lower die to give the proper metal forming operation. Therefore, stops 51, FIG. 2, protrude laterally from the .opposite longitudinal bars 44 of the'bolster 34 to coact with adjustable abutments 62 mounted on the bed of the press between the uprights adjacent the left-hand end of the press. Similarly, stops 63 are mounted on the bolster -35 for engagement with adjustable abutments 64 at the "other side of the press. These locating abutmcnts are adpress and o additionally ascertain the proper location of the bolste r within thepress when it is lowered to engagement with'tlie bed, a pair of locating plugs 65 are mounted in the press bed to be received in recesses 66 formed in the bottom surface of the bolster support bars 44 as seen in 'FIGS. 2 and'o. Only two of these locating plugs are provided one for each support bar 44 and at opposite sides of the press.

The bolsters may be moved back and forth along their track manually or by any suitable drive means. In the present embodiment, a reversible hydraulic motor 67 serves to drive the bolsters back and forth through a gearing arrangement, and this motor is mounted in the bed of the press. As seen in FIGS. 2 and 3, the hydraulic on vertical shafts 73; The shaft 68 and the vertical shafts :73 are rotatably mounted on the press bed. At the upper endslof each shaft 73, a pinion gear 7 is mounted and in aneshing engagement with a rack gear 75 formed along the inner vertical face of the bolster support bars 44, .FIGS. 3 and 6. Thus, the bolsters 34 and 35 may be 'moved back and forth along their respective tracks by operation of the hydraulic motor 67 through the gearing opegation of the press, the bolster within the press is clamped solidly to the press bed inorder to assure stability during operation. This clamping action is accomplished by a pair of elongated T-shaped bars 76, FIGS. 3 and 6, one arranged at the front and the other arranged at the back of the press. Each bar is slidably received in an elongated T-shaped slot or groove 77 formed in the support bars 44 of each bolster. Each bar is further connected to a plurality of spaced piston rods 78 of pneumatic bolster hold down cylinders 79 mounted in the press bed. The elongated T-bars 76 may be as long as desired, but in the instant case are shown to extend between the uprights and terminating at a point spacing inwardly therefrom. Arranging of the T-bars is such that they will always be in alignment with the T-slots 77 of the bolsters, this alignment being assured by the guided rectilinear movement of the bolsters by the tracks 46 and 47. After the bolsters have been lowered to the bed, operation of the pneumatic cylinders 79 securely clamps the bolster 35, as shown in FIG. 3, to the bed weldment of the press. In the instant case, three such bolster hold down cylinders are provided for each T-bar, although more or less may be used according to the needs of the particular installation.

When it is desired to effect a die change, the new or different die may be mounted on the bolster 34, FIG. 3, which is outside of the press without shutting down the press. As the bolster and die changeover begins, the press is shut down and the upper die of the die set within the press is disengaged from the face of the slide 14 by actuation of the die clamps 31 and all of the hydraulic cylinders 5b and 58 are operated to stroke upward and lift both bolsters from firm foundation. Of course, the air in the pneumatic bolster hold down cylinders 79 will have been exhausted therefrom to permit movement of the bolster 35 within the press to move upwardly. This places the bolster wheels 45 of the bolster'35 on level with the tracks 47 mounted flush with the floor on the adjacent side of the press bed and also places into operation the supporting wheels 48 of the hydraulic cylinders 50. Further, the track sections 59 will be moved upwardly and in alignment with the tracks 46 to place the wheels 45 of the bolster 34 on level with the tracks 46 at the other sideof the press bed. In order to assure complete retraction of the die cushion 16, the auxiliary pull down cylinders 23 may be actuated to pull the pressure pad 20 out of the way of the bolster so that it may be moved from the press. Actuation of the hydraulic diive motor 67 then operates the rack and pinion drive to move the bolster 35 out of the press and the bolster 54 into the press to the position as seen in FIG. 10. It may be noted that retracting of the auxiliary pull down cylinders 23 of the die cushions 16 leaves the pressure pin carriers 42 suspended by the ledges 43 of the bolsters as well as bringing the pressure pins 41 flush with the top of the bolster thereby greatly facilitating die changing. These pressure pins need not be removed from the bolster when they are not being used on any particular set up. With the bolsters 3d and 35 in a. position as seen in FIG. 10, the hydraulic cylinders 50 and 58 are operated to lower the bolsters to a firm foundation wherein the bolster 34 will now be within the press and resting on the press bed, while the bolster 35 will be outside of the press and resting on the floor adjacent to the press. In this arrangement, the wheels 45 of the bolster 34will be received in the wheel wells 53- at the inner end of the tracks 46 and the wheels 45 of the bolster 35 will be received in the wheel wells defined by lowering the track sectio 55 on the outer ends of the tracks 47.

It will be appreciated that in driving the bolster 34 and 35 to the positions as seen in FIG. 10, the stops 61 on the bolster 34 will engage the adjustable abutments 62 to stop the movement of the bolsters when they have reached the desired position. The upper die may then be clamped to the face of the slide 14 by the die clamps 31 and the press is then ready for final, adjustment.

Subsequently, the bolster hold down cylinders 79 will be actuated to securely clamp the bolster 34 to the press bed and thereby assure stability of operation and the parts will then be arranged as seen in FIG. 11. ation of the die cushion 16 will then bring the pressure Actupad 20 into engagement with the underside of the pressure pin carrier 42 to urge the pressure pins 41 against the underside of the draw ring as seen in the example of FIG. 12. Operation of the press may then be continued with the new dies, while the old dies may be reof the double bolster arrangement of the first embodiment.

Of course, any number of these single bolsters may be used and this arrangement is such that a single bolster 86 may be moved and carried away from the press by an overhead crane 81 thereby salvaging critical aisle space although this does not affect in any way the concept or function of the moving bolster. When this arrangement is used, die setting may be accomplished in a centralized area of the plant. The single bolster 80 will be provided with four wheels 82, one on each corner instead of two wheels and these wheels will be spaced at a greater distance apart to be received on the tracks 83 which extend through the press and at a point outside of the die cushions. Further, instead of having wells in the tracks, vertically movable track sections, one for each wheel, will be provided to lower the bolster to the press bed. These track sections may be lowered by hydraulic cylinders similar to the arrangements for the sections 55 and 56 on the tracks 46 and 47. It may also be noted that the T-bars 76 are arranged inwardly of the wheels 82. Otherwise, the operation of this modification is identical with that of the first embodiment and also increases the production of any single press by reduc ing the press shut down time.

It will be understood that modifications and variations may be eflected without departing from the scope of 'the novel concepts of the present invention, but it is understood that this application is to be limited only by the scope of the appended claims.

The invention is hereby claimed as follows:

1. In a metal working press having a bed, a crown, uprights between the bed and crown and a slide vertically movable between the uprights, mechanism for easily and quickly replacing die sets in said press thereby reducing press down time comprising, first and second longitudinally aligned bolsters arranged in endato-end relation, tracks on said bed arranged between opposed uprights and extending outwardly from opposite sides of the press, means for connecting the bolsters together at their adjacent ends, wheels on the ends of said bolsters remote from their adjacent ends for movably supporting the bolsters on said tracks, each bolster adapted to receive a die set thereon outside of the press, said die set inleluding upper and lower dies, the lower die of the die set being secured to the bolster outside of the press, means 'for securing the upper die of the die set to the slide when the bolster with the die set is positioned within the press, means within the press coacting with means on the bolster for locating the bolster at a predetermined position on the press bed, each bolster having longitudinally extending support bars at each side thereof, vertically movable rollers mounted on said press bed and adapted to engage the support bars, means for moving said rollers between an upper position which maintains the wheels vof the bolster within the press in alignment with said tracks and a lower position which lowers the bolster within the press to the bed giving it a firm foundation during operation of the press, said support bars of said bolsters having longitudinally extending generally T- shaped grooves therein, longitudinally extending generally T-shaped bars arranged within the confines of the press and aligned to be slidably received by said grooves, and means for moving said bars along the vertical to clamp the bolster within the press to said bed.

2. In a metal working press having a bed, a crown, uprights between the bed and the crown and a slide vertically movable between the uprights, mechanism for easily and quickly replacing die sets in said press thereby reducing press down time comprising, first and second longitudinally aligned bolsters arranged in end-to-end relation, tracks on said bed arranged between opposed uprights and extending outwardly from opposite sides of the press, means for connecting the bolsters together at their adjacent ends, said means including a horizontally extending pivot pin carried by one of the bolsters and received in an aperture of the other bolster, whereby said connecting means will absorb the normal reaction of the bolster in the bed to the pressure of the slide during press operation and thereby prevent deflection of the bolster being set up outside of the prms, wheels on the ends of said bolsters remote from their adjacent ends for movably supporting the bolsters on said tracks, each bolster adapted to receive a die set thereon outside of the press, said die set including upper and lower dies, the lower die of the die set being secured to the bolster outside of the press, means for securing the upper die of the die set to the slide when the bolster with the die! set is positioned within the press, means within the press coacting with means on the bolster for locating the bolster at a predetermined position on the press bed, each bolster having longitudinally extending support bars at each side thereof, vertically movable rollers mounted on said press bed and adapted to engage the support bars, means for moving said rollers between an upper position which maintains the wheels of the bolster within the press in alignment with said tracks and a lower position which lowers the bolsters within the press to the bed giving it a firm foundation during operation of the press, said support bars of said bolsters having longitudinally extending generally T-shaped grooves therein, longitudinally extending generally T-shaped bars arranged within the confines of the press and aligned to be slidably received by said grooves, and means for moving said bars along the vertical to clamp the bolster within the press to said bed.

3. A metal working press adapted for quickly and easily replacing die sets in the press thereby reducing shut down time, said press comprising a bed, a crown, uprights between the bed and crown, a slide vertically movable between the uprights and adapted to have the upper die of a die set secured thereto, a die cushion mounted in the bed and below the top surface thereof, a bolster movable in and out of said press along a rectilinear path and adapted to receive a die set outside of the press and have the lower die of the die set secured thereto and to carry the die set into the press, means for securing the upper die of the die set to the slide when the bolster with the die set is positioned within the press, means within the press coacting with means on the bolster for locating the bolster at a predetermined position on the press bed, and means for lowering the bolster to the bed prior to the press operation thereby giving it a firm foundation, said bolster having a movable pressure pin carrier adapted to be engaged by said die cushion when the bolster is arranged within the press, holes formed in the bolster, and vertically extending pressure pins slidably received in said holes and having their lower ends resting on said pressure pin carrier, the upper ends of said pressure pins adapted to be arranged to engage the draw ring of the die set.

4. A metal working press adapted for quickly an easily replacing die sets in the press thereby reducing shut down time, said press comprising a bed, a crown, uprights between the bed and crown, a slide vertically movable between the uprights and adapted to have the upper die of a die set secured thereto, a die cushion mounted in the bed and below the top surface thereof, a pair of movable bolsters pivotally connected together in end-to-end relation to pivot relative to each other about a horizontal axis and capable of being alternately utilized by said press wherein one of said bolsters is outside of said press when the other bolster is in use in the press thereby permitting mounting of a die set on said bolsteroutside of the press while the press is operating, each bolster alternately movable in and out of said press and adapted to receive a die set thereon when located outside of said press and have the lower die of the die set secured thereto and to carry the die set into the press, means for securing the upper die of the die set to the slide when the bolster with the die set is positioned within the press, each bolster having holes formed therein, pressure pins slidably received in said holes, a pressure pin carrier movably supported by each bolster upon which one end of said pins may rest, the other end of said pressure pins adapted to be arranged to engage a draw ring of said die and said pressure pin carrier adapted to be engaged by said die cushion, wheels on said bolsters, track means arranged within said press for supporting the bolsters and receiving the wheels thereof and guiding the bolsters along a rectilinear path into and out of said press, means for positioning each bolster within said press at a predetermined location along said bed relative to said slide, and means for lowering the bolster within the press to said bed for giving it a firm foundation.

5. A metal working press adapted for quickly and easily replacing die sets in the press thereby reducing shut down time, said press comprising a bed, a crown, uprights between the bed and crown, a slide vertically movable between the uprights and adapted to have the upper die of a die set secured thereto, a die cushion mounted in the bed and below the top surface thereof, a bolster movable in and out of said press along a rectilinear path and adapted to receive a die set outside of the press and have the lower die of the die set secured thereto and to carry the die set into the press, means for securing the upper die of the die set to the slide when the bolster with the die set is positioned within the press, means within the press coacting with means on the bolster for locating the bolster at a predetermined position on the press bed, and means for lowering the bolster to the bed prior to the press operation thereby giving it a firm foundation, said bolster having said die cushion when the bolster is arranged within the press, holes formed in the bolster, and vertically extending pressure pins slidably received in said holes and having their lower ends resting on said pressure pin carrier.

6. A metal working press adapted for quickly and easily replacing die sets in the press thereby reducing shut down time, said press comprising a bed, a crown, uprights between the bed and crown, a slide vertically movable between the uprights and adapted to have the upper die of a die set secured thereto, a die cushion mounted in the bed and below the top surface thereof, a bolster movable in and out of said press along a rectilinear path and adapted to receive a die set outside of the press and have the lower die of the die set secured thereto and to carry the die set into the press, means for securing the upper die of the die set to the slide when the bolster with the die set is positioned within the press, means within the press coacting with means on the bolster for locating the bolster at a predetermined position on the press bed, a plurality of substantially vertically extending holes formed in said bolster, pressure pins slidably received in at least some of said holes and adapted to be movable in said holes by said die cushion and in alignment therewith when the bolster is arranged within the press, and means permanently carried on the bolster in coacting engagement with said pins to limit the downward movement of said pins so that the pins may be carried by the bolster during movement thereof onto and oil of the press bed.

References Cited in the file of this patent UNITED STATES PATENTS 1,891,976 Goebel Dec. 27, 1932 2,013,320 Shank et al Sept. 3, 1935 2,040,731 Ernst May 12, 1936 2,186,799 Boker Jan. 9, 1940 2,211,621 Hoch Aug. 13, 1940 2,317,440 Cannon Apr. 27, 1943 2,327,117 Lorant Aug. 17, 1943 2,332,135 Dievers Oct. 19, 1943 2,543,498 Iapikse Feb. 27, 1951 2,751,872 Hodes June 26, 1956 2,757,414 Chaloupka Aug. 7, 1956 2,796,253 Schulze et a1 June 18, 1957 FOREIGN PATENTS 128,570 Great Britain 1921 875,339 France June 15, 1942 UNITED STATES PATENT OFFICE CERTIFICATION OF ICORRECTIION Patent No. 3,002,479 October 3, 1961 Einar K. Johansen et a1,

It is Hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Petent should read as corrected below.

Column 4 line 8, for "or" read of column 5, line for "support" read supporting Signed and sealed this 3rd day of April 1962,

(SEAL) Attest:

ERNEST W. SWIDER Commissioner of Patents 

